// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_FILEAPI_CHROME_BLOB_STORAGE_CONTEXT_H_
#define CONTENT_BROWSER_FILEAPI_CHROME_BLOB_STORAGE_CONTEXT_H_

#include <stddef.h>
#include <stdint.h>

#include <memory>

#include "base/files/file_path.h"
#include "base/memory/ref_counted.h"
#include "base/sequenced_task_runner_helpers.h"
#include "content/common/content_export.h"

namespace base {
class FilePath;
class TaskRunner;
class Time;
}

namespace storage {
class BlobStorageContext;
}

namespace content {
class BlobHandle;
class BrowserContext;
struct ChromeBlobStorageContextDeleter;

// A context class that keeps track of BlobStorageController used by the chrome.
// There is an instance associated with each BrowserContext. There could be
// multiple URLRequestContexts in the same browser context that refers to the
// same instance.
//
// All methods, except the ctor, are expected to be called on
// the IO thread (unless specifically called out in doc comments).
class CONTENT_EXPORT ChromeBlobStorageContext
    : public base::RefCountedThreadSafe<ChromeBlobStorageContext,
          ChromeBlobStorageContextDeleter> {
public:
    ChromeBlobStorageContext();

    static ChromeBlobStorageContext* GetFor(
        BrowserContext* browser_context);

    void InitializeOnIOThread(base::FilePath blob_storage_dir,
        scoped_refptr<base::TaskRunner> file_task_runner);

    storage::BlobStorageContext* context() const { return context_.get(); }

    // Returns a NULL scoped_ptr on failure.
    std::unique_ptr<BlobHandle> CreateMemoryBackedBlob(const char* data,
        size_t length);

    // Returns a NULL scoped_ptr on failure.
    std::unique_ptr<BlobHandle> CreateFileBackedBlob(
        const base::FilePath& path,
        int64_t offset,
        int64_t size,
        const base::Time& expected_modification_time);

protected:
    virtual ~ChromeBlobStorageContext();

private:
    friend class base::DeleteHelper<ChromeBlobStorageContext>;
    friend class base::RefCountedThreadSafe<ChromeBlobStorageContext,
        ChromeBlobStorageContextDeleter>;
    friend struct ChromeBlobStorageContextDeleter;

    void DeleteOnCorrectThread() const;

    std::unique_ptr<storage::BlobStorageContext> context_;
};

struct ChromeBlobStorageContextDeleter {
    static void Destruct(const ChromeBlobStorageContext* context)
    {
        context->DeleteOnCorrectThread();
    }
};

} // namespace content

#endif // CONTENT_BROWSER_FILEAPI_CHROME_BLOB_STORAGE_CONTEXT_H_
